Circular RNA circAGO2 drives cancer progression through facilitating HuR-repressed functions of AGO2-miRNA complexes

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Abstract

Argonaute 2 (AGO2), the core component of microRNA (miRNA)-induced silencing complex, plays a compelling role in tumorigenesis and aggressiveness. However, the mechanisms regulating the functions of AGO2 in cancer still remain elusive. Herein, we indentify one intronic circular RNA (circRNA) generated from AGO2 gene (circAGO2) as a novel regulator of AGO2-miRNA complexes and cancer progression. CircAGO2 is up-regulated in gastric cancer, colon cancer, prostate cancer, and neuroblastoma, and is associated with poor prognosis of patients. CircAGO2 promotes the growth, invasion, and metastasis of cancer cells in vitro and in vivo. Mechanistic studies reveal that circAGO2 physically interacts with human antigen R (HuR) protein to facilitate its activation and enrichment on the 3’-untranslated region of target genes, resulting in reduction of AGO2 binding and repression of AGO2/miRNA-mediated gene silencing associated with cancer progression. Pre-clinically, administration of lentivirus-mediated short hairpin RNA targeting circAGO2 inhibits the expression of downstream target genes, and suppresses the tumorigenesis and aggressiveness of xenografts in nude mice. In addition, blocking the interaction between circAGO2 and HuR by cell-penetrating inhibitory peptide represses the tumorigenesis and aggressiveness of cancer cells. Taken together, these results indicate that oncogenic circAGO2 drives cancer progression through facilitating HuR-repressed functions of AGO2-miRNA complexes.

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References

  1. 1.

    Meister G, Landthaler M, Patkaniowska A, Dorsett Y, Teng G, Tuschl T. Human Argonaute 2 mediates RNA cleavage targeted by miRNAs and siRNAs. Mol Cell. 2004;15:185–97.

  2. 2.

    Shen J, Xia W, Khotskaya YB, Huo L, Nakanishi K, Lim SO, et al. EGFR modulates microRNA maturation in response to hypoxia through phosphorylation of AGO2. Nature. 2013;497:383–7.

  3. 3.

    Huntzinger E, Izaurralde E. Gene silencing by microRNAs: contributions of translational repression and mRNA decay. Nat Rev Genet. 2011;12:99–110.

  4. 4.

    Zhang J, Fan XS, Wang CX, Liu B, Li Q, Zhou XJ. Up-regulation of Ago2 expression in gastric carcinoma. Med Oncol. 2013;30:628.

  5. 5.

    Papachristou DJ, Korpetinou A, Giannopoulou E, Antonacopoulou AG, Papadaki H, Grivas P, et al. Expression of the ribonucleases Drosha, Dicer, and Ago2 in colorectal carcinomas. Virchows Arch. 2011;459:431.

  6. 6.

    Yoo NJ, Hur SY, Kim MS, Lee JY, Lee SH. Immunohistochemical analysis of RNA-induced silencing complex-related proteins AGO2 and TNRC6A in prostate and esophageal cancers. APMIS. 2010;118:271–6.

  7. 7.

    Qu H, Zheng L, Song H, Jiao W, Li D, Fang E, et al. microRNA-558 facilitates the expression of hypoxia-inducible factor 2 alpha through binding to 5′-untranslated region in neuroblastoma. Oncotarget. 2016;7:40657–73.

  8. 8.

    Zhang Y, Wang B, Chen X, Li W, Dong P. AGO2 involves the malignant phenotypes and FAK/PI3K/AKT signaling pathway in hypopharyngeal-derived FaDu cells. Oncotarget. 2017;8:54735–46.

  9. 9.

    Jeck WR, Sharpless NE. Detecting and characterizing circular RNAs. Nat Biotechnol. 2014;32:453–61.

  10. 10.

    Chen J, Li Y, Zheng Q, Bao C, He J, Chen B, et al. Circular RNA profile identifies circPVT1 as a proliferative factor and prognostic marker in gastric cancer. Cancer Lett. 2017;388:208–19.

  11. 11.

    Hsiao KY, Lin YC, Gupta SK, Chang N, Yen L, Sun HS, et al. Noncoding effects of circular RNA CCDC66 promote colon cancer growth and metastasis. Cancer Res. 2017;77:2339–50.

  12. 12.

    Huang XY, Huang ZL, Xu YH, Zheng Q, Chen Z, Song W, et al. Comprehensive circular RNA profiling reveals the regulatory role of the circRNA-100338/miR-141-3p pathway in hepatitis B-related hepatocellular carcinoma. Sci Rep. 2017;7:5428.

  13. 13.

    Bachmayr-Heyda A, Reiner AT, Auer K, Sukhbaatar N, Aust S, Bachleitner-Hofmann T, et al. Correlation of circular RNA abundance with proliferation-exemplified with colorectal and ovarian cancer, idiopathic lung fibrosis, and normal human tissues. Sci Rep. 2015;5:8057.

  14. 14.

    Wang K, Sun Y, Tao W, Fei X, Chang C. Androgen receptor (AR) promotes clear cell renal cell carcinoma (ccRCC) migration and invasion via altering the circHIAT1/miR-195-5p/ 29a-3p/29c-3p/CDC42 signals. Cancer Lett. 2017;394:1–12.

  15. 15.

    Weng W, Wei Q, Toden S, Yoshida K, Nagasaka T, Fujiwara T, et al. Circular RNA ciRS-7-A promising prognostic biomarker and a potential therapeutic target in colorectal cancer. Clin Cancer Res. 2017;23:3918–28.

  16. 16.

    Wilusz JE, Sharp PA. A circuitous route to noncoding RNA. Science. 2013;340:440–1.

  17. 17.

    Du WW, Yang W, Liu E, Yang Z, Dhaliwal P, Yang BB. Foxo3 circular RNA retards cell cycle progression via forming ternary complexes with p21 and CDK2. Nucleic Acids Res. 2016;44:2846–58.

  18. 18.

    Glažar P, Papavasileiou P, Rajewsky N. circBase: a database for circular RNAs. RNA. 2014;20:1666–70.

  19. 19.

    Petkovic S, Muller S. RNA circularization strategies in vivo and in vitro. Nucleic Acids Res. 2015;43:2454–65.

  20. 20.

    Agostini F, Zanzoni A, Klus P, Marchese D, Cirillo D, Tartaglia GG. catRAPID omics: a web server for large-scale prediction of protein-RNA interactions. Bioinformatics. 2013;29:2928–30.

  21. 21.

    Walia RR, Xue LC, Wilkins K, El-Manzalawy Y, Dobbs D, Honavar V. RNABindRPlus: a predictor that combines machine learning and sequence homology-based methods to improve the reliability of predicted RNA-binding residues in proteins. PLoS One. 2014;9:e97725.

  22. 22.

    Lopez de Silanes I, Zhan M, Lal A, Yang X, Gorospe M. Identification of a target RNA motif for RNA-binding protein HuR. Proc Natl Acad Sci USA. 2004;101:2987–92.

  23. 23.

    Balkhi MY, Iwenofu OH, Bakkar N, Ladner KJ, Chandler DS, Houghton PJ, et al. miR-29 acts as a decoy in sarcomas to protect the tumor suppressor A20 mRNA from degradation by HuR. Sci Signal. 2013;6:ra63.

  24. 24.

    Yang YC, Di C, Hu B, Zhou M, Liu Y, Song N, et al. CLIPdb: a CLIP-seq database for protein-RNA interactions. BMC Genom. 2015;16:51.

  25. 25.

    Fallmann J, Sedlyarov V, Tanzer A, Kovarik P, Hofacker IL. AREsite2: an enhanced database for the comprehensive investigation of AU/GU/U-rich elements. Nucleic Acids Res. 2016;44:D90–D95.

  26. 26.

    Zhang JH, Seigneur EM, Pandey M, Loshakov A, Dagur PK, Connelly PS, et al. The EIF4EBP3 translational repressor is a marker of CDC73 tumor suppressor haploinsufficiency in a parathyroid cancer syndrome. Cell Death Dis. 2012;3:266.

  27. 27.

    Tentu S, Nandarapu K, Muthuraj P, Venkitasamy K, Venkatraman G, Rayala SK. DHQZ-17, a potent inhibitor of the transcription factor HNF4A, suppresses tumorigenicity of head and neck squamous cell carcinoma in vivo. J Cell Physiol. 2018;233:2613–28.

  28. 28.

    Yang HS, Matthews CP, Clair T, Wang Q, Baker AR, Li CC, et al. Tumorigenesis suppressor Pdcd4 down-regulates mitogen-activated protein kinase kinase kinase kinase 1 expression to suppress colon carcinoma cell invasion. Mol Cell Biol. 2006;26:1297–306.

  29. 29.

    Fukusumi T, Guo TW, Sakai A, Ando M, Ren S, Haft S, et al. The NOTCH4–HEY1 pathway induces epithelial–mesenchymal transition in head and neck squamous cell carcinoma. Clin Cancer Res. 2018;24:619–33.

  30. 30.

    Chang YC, Chi LH, Chang WM, Su CY, Lin YF, Chen CL. et al. Glucose transporter 4 promotes head and neck squamous cell carcinoma metastasis through the TRIM24-DDX58 axis. J Hematol Oncol. 2017;10:11

  31. 31.

    Mattie M, Raitano A, Morrison K, Morrison K, An Z, Capo L, et al. The discovery and preclinical development of ASG-5ME, an antibody–drug conjugate targeting SLC44A4-positive epithelial tumors including pancreatic and prostate cancer. Mol Cancer Ther. 2016;15:2679–87.

  32. 32.

    Dweep H, Gretz N. miRWalk2.0: a comprehensive atlas of microRNA-target interactions. Nat Methods. 2015;12:697.

  33. 33.

    Dudekula DB, Panda AC, Grammatikakis I, De S, Abdelmohsen K, Gorospe M. CircInteractome: A web tool for exploring circular RNAs and their interacting proteins and microRNAs. RNA Biol. 2016;13:34–42.

  34. 34.

    Wu X, Lan L, Wilson DM, Marquez RT, Tsao WC, Gao P, et al. Identification and validation of novel small molecule disruptors of HuR-mRNA interaction. ACS Chem Biol. 2015;10:1476–84.

  35. 35.

    Memczak S, Jens M, Elefsinioti A, Torti F, Krueger J, Rybak A, et al. Circular RNAs are a large class of animal RNAs with regulatory potency. Nature. 2013;495:333–8.

  36. 36.

    Zhang Y, Zhang XO, Chen T, Xiang JF, Yin QF, Xing YH, et al. Circular intronic long noncoding RNAs. Mol Cell. 2013;51:792–806.

  37. 37.

    Li Z, Huang C, Bao C, Chen L, Lin M, Wang X, et al. Exon-intron circular RNAs regulate transcription in the nucleus. Nat Struct Mol Biol. 2015;22:256–64.

  38. 38.

    Qu S, Liu Z, Yang X, Zhou J, Yu H, Zhang R, et al. The emerging functions and roles of circular RNAs in cancer. Cancer Lett. 2018;414:301–9.

  39. 39.

    Li F, Zhang L, Li W, Deng J, Zheng J, An M, et al. Circular RNA ITCH has inhibitory effect on ESCC by suppressing the Wnt/β-catenin pathway. Oncotarget. 2015;6:6001–13.

  40. 40.

    Han D, Li J, Wang H, Su X, Hou J, Gu Y, et al. Circular RNA circMTO1 acts as the sponge of microRNA-9 to suppress hepatocellular carcinoma progression. Hepatology. 2017;66:1151–64.

  41. 41.

    Schmidt C, Kramer K, Urlaub H. Investigation of protein-RNA interactions by mass spectrometry-techniques and applications. J Proteom. 2012;75:3478–94.

  42. 42.

    Fan XC, Steitz JA. Overexpression of HuR, a nuclear-cytoplasmic shuttling protein, increases the in vivo stability of ARE-containing mRNAs. EMBO J. 1998;17:3448–60.

  43. 43.

    Melling N, Taskin B, Hube-Magg C, Kluth M, Minner S, Koop C, et al. Cytoplasmic accumulation of ELAVL1 is an independent predictor of biochemical recurrence associated with genomic instability in prostate cancer. Prostate. 2016;76:259–72.

  44. 44.

    Doller A, Pfeilschifter J, Eberhardt W. Signalling pathways regulating nucleo-cytoplasmic shuttling of the mRNA-binding protein HuR. Cell Signal. 2008;20:2165–73.

  45. 45.

    Kotta-Loizou I, Giaginis C, Theocharis S. Clinical significance of HuR expression in human malignancy. Med Oncol. 2014;31:161.

  46. 46.

    Wang W, Caldwell MC, Lin S, Furneaux H, Gorospe M. HuR regulates cyclin A and cyclin B1 mRNA stability during cell proliferation. EMBO J. 2000;19:2340–50.

  47. 47.

    Wang W, Yang X, Cristofalo VJ, Holbrook NJ, Gorospe M. Loss of HuR is linked to reduced expression of proliferative genes during replicative senescence. Mol Cell Biol. 2001;21:5889–98.

  48. 48.

    Chang N, Yi J, Guo G, Liu X, Shang Y, Tong T, et al. HuR uses AUF1 as a cofactor to promote p16INK4 mRNA decay. Mol Cell Biol. 2010;30:3875–86.

  49. 49.

    Kim HH, Kuwano Y, Srikantan S, Lee EK, Martindale JL, Gorospe M. HuR recruits let-7/RISC to repress c-Myc expression. Genes Dev. 2009;23:1743–8.

  50. 50.

    Cheng YC, Liou JP, Kuo CC, Lai WY, Shih KH, Chang CY, et al. MPT0B098, a novel microtubule inhibitor that destabilizes the hypoxia-inducible factor-1α mRNA through decreasing nuclear-cytoplasmic translocation of RNA-binding protein HuR. Mol Cancer Ther. 2013;12:1202–12.

  51. 51.

    Bolognani F, Gallani AI, Sokol L, Baskin DS, Meisner-Kober N. mRNA stability alterations mediated by HuR are necessary to sustain the fast growth of glioma cells. J Neurooncol. 2012;106:531–42.

  52. 52.

    Li D, Wang X, Mei H, Fang E, Ye L, Song H, et al. Long noncoding RNA pancEts-1 promotes neuroblastoma progression through hnRNPK-mediated β-catenin stabilization. Cancer Res. 2018;78:1169–83.

  53. 53.

    Zhao X, Li D, Pu J, Mei H, Yang D, Xiang X, et al. CTCF cooperates with noncoding RNA MYCNOS to promote neuroblastoma progression through facilitating MYCN expression. Oncogene. 2016;35:3565–76.

  54. 54.

    Zhang H, Pu J, Qi T, Qi M, Yang C, Li S, et al. MicroRNA-145 inhibits the growth, invasion, metastasis and angiogenesis of neuroblastoma cells through targeting hypoxia-inducible factor 2 alpha. Oncogene. 2014;33:387–97.

  55. 55.

    Li D, Mei H, Pu J, Xiang X, Zhao X, Qu H, et al. Intelectin 1 suppresses the growth, invasion and metastasis of neuroblastoma cells through up-regulation of N-myc downstream regulated gene 2. Mol Cancer. 2015;14:47.

  56. 56.

    Abdelmohsen K, Pullmann R, Lal A, Kim HH, Galban S, Yang X, et al. Phosphorylation of HuR by Chk2 regulates SIRT1 expression. Mol Cell. 2007;25:543–57.

  57. 57.

    Hansen TB, Jensen TI, Clausen BH, Bramsen JB, Finsen B, Damgaard CK, et al. Natural RNA circles function as efficient microRNA sponges. Nature. 2013;495:384–8.

  58. 58.

    Pieper D, Schirmer S, Prechtel AT, Kehlenbach RH, Hauber J, Chemnitz J. Functional characterization of the HuR:CD83 mRNA interaction. PLoS One. 2011;6:e23290.

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Acknowledgements

We appreciate Drs. Myriam Gorospe and Jan Chemnitz for providing vector. This work was granted by the National Natural Science Foundation of China (81272779, 81372667, 81472363, 81402301, 81402408, 81572423, 81672500, 81773094, 81772967, 81874085, 81874066, 81802925), Fundamental Research Funds for the Central Universities (2012QN224, 2013ZHYX003), and Natural Science Foundation of Hubei Province (2014CFA012).

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Correspondence to Liduan Zheng or Qiangsong Tong.

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